another trickle demo: measuring setup time

Since the original trickle demo is now more a demo of candidate gathering here is one that lets the user compare trickle ice and non-trickle. Mashed up from the trickle and munge demos.
Online version: http://fippo.github.io/webrtc/samples/web/content/peerconnection/trickle-effect/

It measures the time between createOffer and iceconnectionstatechange->connected. For the biggest effect I recommend disabling trickle, using a TURN/TCP or TLS server and having a virtualbox interface.

@sw12: might be useful as part of the codelab since it demonstrates why trickle ice is such a great idea :-)